code: def close(fignum=None):  # pragma: no cover
      from matplotlib.pyplot import get_fignums, close as _close
  
      if fignum is None:
          for fignum in get_fignums():
              _close(fignum)
      else:
          _close(fignum)
  
file_path: mars/mars/dataframe/plotting/tests/test_plot.py
imports: import warnings
  import tempfile
  import numpy
  import pandas
  import pytest
  from ....None import tensor
  from ....None import dataframe
label_desc: Use image node_id 1 for calling a global function with example usage: close(fignum) without return types